The reason Absinthe was banned in the first place was that as it grew popular in the late 1800's many unscrupulous makers did awful things to produce it on the cheap and people died.
Since even properly made Absinthe is an "acquired taste", these makers could get away, for awhile at least, using things like wood alcohol, and heavy metals to get the green color. Instead of trying to differentiate between the good and the bad, it was all banned.
Then in later years, people attracted to the cachet of Absinthe, and it's association with various, and often troubled/tragic artists and writers, did stupid things with wormwood trying to replicate the "effects", adding to the popular notion that Absinthe is more dangerous than other alcohols.
I've read some level-headded speculation that what made Absinthe "special" was not really the wormwood, since the ammount needed of the toxin to produce any effects is so close to the level at wich it was poisonous. Instead, they focused on all the other herbs in the recipie, and many have stimulant effects, similar to caffine or ephedra, and it's thought that the "lucid high" was simply that counteracting the alcohol buzz.
A couple of cauppichinos spiked with some Sambuca will get you that.
I read in a magazine, (Wired?, I forget...) there was some scientist in New Orleans who'd found an old bottle of high-quality Absinthe and ran it through a mass spectrometer to get all the components, and was reverse engineering the original recipies, and according to him, it was "quite different" than what's being sold as "genuine Absinthe" today, it actualy has several redeeming aspects to it's taste and odor, and the level of thujone from the wormwood was not significant enough to be toxic.
I don't know if Katrina wiped out his efforts or not.